Definition of Altered state of consciousness

An altered state of consciousness is any condition which is significantly different from a normative waking beta wave state. The expression was coined by Charles Tart and describes induced changes in one's mental state, almost always temporary. A synonymous phrase is "altered states of awareness". An associated body of research has been conducted in trance and this is becoming the predominant auspice terminology. Trance includes all "altered states of consciousness" as well as the various forms of waking trance states.